
Fans posting on the game’s official forum claim that the bug kicks after 50 to 120 hours of gameplay when the new expansion has been installed, with items randomly disappearing from the world.
According to the forum, the reference IDs of objects generated in the game have a finite space allocated and once this space has been filled the game rolls back to the first available ID number and begins overwriting the old objects.
In Shivering Isles, the reference IDs be generated at a very high speed, drastically shortening the play-time. Depending on how vigorously the game is played will depend on how many new reference IDs are generated and how soon the glitch appears.
Bethesda has acknowledged the bug on the PC and has issued an emergency patch. It is not yet confirmed whether the Xbox 360 version is at fault too.
The developer advises to back up your save games when using the patch and be prepared for more trouble as the patch is only a beta.